Speaking head



June 16, 1.936- K. voN HElslNG SPEAKINGIHEAD Fued oct. 4, 1934 WIG? Patented June 16, 1936 UNITED STATES SPEAKING HEAD kurt von neming, Mm mu. England, min-mr to Stille Inventions Limited, London, England Application October 4,1934, Serial No. 746,865

In' Great Britain October 9, 1933 3Claims.

This invention relates to a speaking head for telegraphones and the like' ofthe Poulsen system and oi' the kind divided into two hinged portions between which and between spring-pressed pole pieces in said portions, the wire or tape is guided.

The object of the invention is to obtain additional facilities for manipulating the speaking head, and the invention consists in hinging the two portions of the head to a rigid supporting base allowing them, when opened out, to be separated from the tape so as to leave the latter in a completely isolated position and so as to leave the magnet faces free for the convenient manipulation of the pole pieces, means being provided for convenient adjustment of the spring pressure on the pole pieces and for' relieving the lat ter of pressure without disturbing the spring adjustment, while the head is being opened and closed.

Fig. 1 o! the accompanying drawing represents a side view' of a speaking head constructed according to the invention, one head portion being shown in section.

Fig. 2 is a side view on a smaller scaley showing the head open, and y Fig. 3 is a plan view oi' Fig. 2.

The speaking head is divided into two, co-operating portions a and b each provided with a magnet coil c within which a pole piece d is arranged to slide. The two head portions vnormally abut against each other, and the pole pieces bear from opposite sides and under spring pressure4v against a record carrier, preferably in the form ot a steel tape e which travels through a guideway f made li'or, it in the pole face of one or both head portions. Felt pads a may be let into the.

face along the guideway as a means for steadying the recording tape.

' According to-the invention, the head portions are hinged at h and i'respectively to a rigidsupporting base k which is normally covered by the two head portions, as shown in Fig. 1, andwhich allows the head to be opened out as shown in Figs. 2 and 3, in order to separate it from the tape e. It will be seen in Fig. 2 that the -tape is left by the opened out head portions in a completely isolated position and that the pole pieces are lett perfectly tree for convenient manipulation and exchange.

Spring pressure is applied to each pole piece through the medium oi' a plunger l which is guided partly in a sleeve mand partly in a screwv cap n applied tothe sleeve, the plunger being connected to a rod o whlch'is encircled by the Y spring p and which is arranged to slide in'an ap- (Ci. )J9-100.2)

erture in the cap. 'Ihe spring p bears at one end against the plunger and at the other end against the cap which is adjusted on the sleeve m 4in order to regulate the spring pressure applied to the pole piece. In order to allow this regulation to take place under strict control, the cap is provided with graduations and is adjusted with reterence to an index q.

It is essential that the pole pieces should be relieved of pressure while the head is being 10 opened and closed and for this purpose the rod o is iitted, outside the cap n, with a knob r by means of which the plunger l can be retracted in opposition to the spring.` A pin s, which is secured to the cap and which normally engages in an aperture in the knob, serves as a support for retaining the plunger in retracted position, the knob and plunger being for this purpose turned through a small angle so as to throw the aperture in the knob out 'of register with the pin.

'A slotted plate t which is hinged to one oi' the head portions is adapted to be turned into engagement with a s tud u on the other portion f or locking the two portions in closed andoperative position.

'Ihe hinge h of the head portion a is made so as to enable this portion to be displaced in the direction of the hinge pin for staggering the two pole pieces in known manner in the direction oi' travel of the recording tape. 'Ihe adjustment is 30 effected through the medium of a nut v which .Mworks on a screw :c within a yoke y and which is provided with micrometer reading, the screw bein'g connected to the head portion a while the yoke is connected to a bracket 'z onl the base lc 36 and pivots together with the head portion about the pin of the hinge h.

'I'he speaking head is provided as usual with terminalsi by means oi which it is connected to an electric circuit.

I claim:

1. rA speaking head for telegraphones comprising two co-operating head portions adapted to guide a travelling recording member between them, a rigid supporting baseto which both head 45.

piece, and means for retaining the plunger vin n retracted position.

2. A speaking head for telegraphones com` prising two co-operating head portions adapted to guide a travelling recording member between them, a. rigid supporting base to which both head portions are hinged for application to and sep' aration from said recording member, a slidable pole piece in each head portion, a plunger abutting against said pole piece, a screw cap serving as guide for said plunger, a spring bearing against said cap and against the plunger for applying the latter to the pole piece, means for retracting the plunger from the pole piece, and means for retaining the plunger in retracted position, the screw cap being adjustable for regulating the plunger pressure.

3. A speaking head for telegraphcnes comprising two Jo-operating head portions adapted to guide a travelling recording member between them, a rigid supporting base to which both head portions are hinged for application to and separation from said recording member, a sldable pole piece in each head portion, a plunger abutting against said pole piece, a screw cap serving as guide for said plunger, a spring bearing against the cap and against the plunger for applying the latter to the pole piece, a knob secured to the outer end of the plunger, and an 1 abutment on the screw cap adapted, after rotary displacement of said knob from its normal position, to co-operate with the knob for maintaining the plunger in inoperative position, said screw cap being adjustable for regulating the pressure of the plunger on the pole piece.

KURT voN HEISING. 

